1. Field of the Invention
The present invention relates to an electron beam exposure system and an electron beam apparatus for exposing a medium by continuously moving a stage supporting said medium.
2. Description of the Prior Art
The electron beam exposure system is well known as a method for forming minute patterns of an LSI (Large Scale Integrated Circuit). This electron beam exposure system is classified into (1) the step and repeat system where patterns are depicted on the wafer by repeating a process that a wafer is exposed by, for example, a variable rectangular beam, then shifted by one step and then exposed by said beam by shifting the stage mounting said wafers step by step, and (2) the continuous stage moving system where patterns are depicted by projecting the beam to the wafers while said stage is always moved continuously.
In the former system, the electron beam deflection range is comparatively as wide as 2 (two) to 5 (five) mm square, and the stage moves 2 to 5 mm in a direction and stops to project the electron beam on a wafer and then moves 2 to 5 mm after the projection. The exposed portions are thus sequentially formed by repeating such operations. In the latter system, the stage moves continuously at a rate of about 20 mm/sec, a beam is scanned in the range as narrow as about 250 .mu.m at the right angle to the moving direction of the wafer, and thereby patterns are depicted on the wafers.
The former step and repeat system has merit in that the beam position control is easy at the time of depicting patterns since the stage is in the stationary condition. However, this system also has demerit in that compensation for obscurity, such as distortion, field curvature, astigmatism, etc., is required since the deflection width of the electron beam is wide and movement of the stage lacks smoothness because it is moved step by step for every pattern depiction and always subjected to acceleration and deceleration. On the other hand, the latter continuous stage moving system has merit in that the stage moves smoothly and naturally on account of the continuous movement of the stage and the variety of compensations mentioned above are not required due to the narrow deflection of the electron beam. However, this system also has demerit in that the beam position control is complicated due to the continuous movement of the stage, a narrow deflection of electron beam provides less amount of exposing process, and thereby a longer period is required for depicting desired patterns.